Contrasts in growth and nitrogen nutrition of species in the Cupressaceae and Pinaceae in response to calcium

Hawkins, Barbara J.; Robbins, Samantha

doi:10.1007/s11104-014-2093-x

Cited by 5 publications

(3 citation statements)

References 31 publications

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“…Overstory Thuja also occurred in 20% of plots, mainly in stands >90 years old but sometimes in relatively young stands 34–55 years old, unlike the findings of Stolnack and Naiman (), because they did not examine forests along the lower segment where almost all of the Thuja we observed were located. Higher soil calcium and magnesium in the lower segment may have contributed to higher Thuja abundance (Hawkins and Robbins ; Perry et al., in press).…”

Section: Discussionmentioning

confidence: 99%

Effects of dams and geomorphic context on riparian forests of the Elwha River, Washington

et al. 2016

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Abstract. Understanding how dams affect the shifting habitat mosaic of river bottomlands is key for protecting the many ecological functions and related goods and services that riparian forests provide and for informing approaches to riparian ecosystem restoration. We examined the downstream effects of two large dams on patterns of forest composition, structure, and dynamics within different geomorphic contexts and compared them to upstream reference conditions along the Elwha River, Washington, USA. Patterns of riparian vegetation in river segments downstream of the dams were driven largely by channel and bottomland geomorphic responses to a dramatically reduced sediment supply. The river segment upstream of both dams was the most geomorphically dynamic, whereas the segment between the dams was the least dynamic due to substantial channel armoring, and the segment downstream of both dams was intermediate due to some local sediment supply. These geomorphic differences were linked to altered characteristics of the shifting habitat mosaic, including older forest age structure and fewer young Populus balsamifera subsp. trichocarpa stands in the relatively static segment between the dams compared to more extensive early-successional forests (dominated by Alnus rubra and Salix spp.) and pioneer seedling recruitment upstream of the dams. Species composition of later-successional forest communities varied among river segments as well, with greater Pseudotsuga menziesii and Tsuga heterophylla abundance upstream of both dams, Acer spp. abundance between the dams, and P. balsamifera subsp. trichocarpa and Thuja plicata abundance below both dams. Riparian forest responses to the recent removal of the two dams on the Elwha River will depend largely on channel and geomorphic adjustments to the release, transport, and deposition of the large volume of sediment formerly stored in the reservoirs, together with changes in large wood dynamics.

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Section: Discussionmentioning

confidence: 99%

Effects of dams and geomorphic context on riparian forests of the Elwha River, Washington

et al. 2016

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“…Nutrients of interest (NO3 -, NH4 + , PO4 3-, and Ca 2+ ) were selected based on previous studies (Hawkins andRobbins 2014, Trant et al 2016) indicating their importance in the Cupressaceae family (of which coast redwood is a member) or other temperate forest ecosystems (Wardle et al 2004, Binkley andFisher 2013). For example, multiple species in the Cupressaceae family establish well on calcareous soils or have high foliar Ca 2+…”

Section: List Of Tablesmentioning

confidence: 99%

“…on pH and Cupressaceae tolerance to the calcareous environment (Hawkins andRobbins 2014, Trant et al 2016). Nitrogen (NO3 -, NH4 + ) and PO4 3supply are also important factors in forest productivity across many species (Wardle et al 2004, Binkley andFisher 2013), and NO3is of particular importance to western red cedar in the Cupressaceae family (Bennett and Prescott 2004).…”

Section: List Of Tablesmentioning

confidence: 99%

Compounding Fire Disturbance History Encourages Coast Redwood (Sequoia sempervirens) Regeneration and Community Dominance

Brousil¹

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Disturbance is fundamental to forest ecosystem function and overall health, but climate change is likely to increase both disturbance frequency and intensity in the future. Forests subject to increasingly frequent and intense disturbances are more likely to experience compounding disturbance effects. Compounding disturbances may exert unpredicted, non-additive stresses on ecosystems, leading to novel conditions that may exceed the capacity for local species to survive and regenerate. I further hypothesize that compounding disturbances could create conditions misaligned with species' adaptations by altering physical and chemical growing conditions in forest soils, affecting forest composition, structure, and, subsequently, function for many years following disturbance. A better understanding of these remnant effects will be essential to managing and conserving coast redwood forests, which are projected to see increased frequency of fire under future climate scenarios. My objectives in this study were to quantify the effects of time-since-fire and single vs. compounding disturbances on coast redwood forest structure, composition, and regeneration dynamics and to evaluate the effects of abiotic soil qualities on post-fire regeneration. I mapped and sampled coast redwood forests burned in 1985, both 1985 and 1999, 2008, and 2013; modeled regeneration as a function of burn history, understory light, and post-fire nutrient levels; and tested redwood seed regeneration in post-fire soils in a greenhouse experiment. Forest structure, composition, and regeneration following compounding disturbance were most similar to the v homogenous, redwood-dominated forest of the recent 2013 burn. There were no unique effects of compounding disturbance on soil nutrient levels, although variations in nutrient levels generally followed patterns seen in previous studies. Soil nitrate was positively associated with coast redwood regeneration levels, showing that soil nutrients may be influential in regeneration processes following disturbance. Time since burn and single burn histories were negatively associated with regeneration levels in the field, and there were no differences in seed germination in the greenhouse between soils from different fire histories. Increases in coast redwood forest dominance accompanied declines in bay laurel and tanoak presence, indicating a shift in post-fire forest structure and composition resulting from compounding disturbance. These results illustrate a complex relationship between regeneration dynamics, post-fire soil quality, and disturbance histories. Forest homogenization from compounding disturbances may have negative implications for ecosystem services and overall function if compounding disturbances are more frequent as predicted under future climate conditions.

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Riparian Soil Development Linked to Forest Succession Above and Below Dams Along the Elwha River, Washington, USA

2016

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Contrasts in growth and nitrogen nutrition of species in the Cupressaceae and Pinaceae in response to calcium

Cited by 5 publications

References 31 publications

Effects of dams and geomorphic context on riparian forests of the Elwha River, Washington

Effects of dams and geomorphic context on riparian forests of the Elwha River, Washington

Compounding Fire Disturbance History Encourages Coast Redwood (Sequoia sempervirens) Regeneration and Community Dominance

Riparian Soil Development Linked to Forest Succession Above and Below Dams Along the Elwha River, Washington, USA

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